Occupational Contact Dermatitis

Dr Amy Burdzik

MBChB, MMed, FCPHM Occ Med (SA)

OCCUPATIONAL MEDICINE DIVISION

School of Public Health and Family Medicine

University of Cape Town, South Africa

ALLSA Congress, Port Elizabeth, September 2017

Overview

• Common occupational skin diseases

• Evaluating a patient with possible occupational skin disease

• Managing occupational skin disease• Treatment

• Referral

Occupational skin disease

IRRITANT

Acute Chronic

Irritantcontact

dermatitis

ALLERGIC

Allergic contact

dermatitis

(Type IV)

Protein contact

dermatitis

(?Type 1 & Type IV)

Immunologiccontact urticaria

(Type 1)

OTHER

Non-immunologic

contact urticaria

Skin cancer

Pigmentation disorders

Infections

Acne

Pathophysiology allergic contact dermatitis: Type IV hypersensitivity

Source: Saito et al, 2016

Patch test for delayed hypersensitivity

Small haptenspenetrate the skin. Initiate production of pro-inflammatory cytokines and chemokines

Hapten presented on Major Histocompatibility Complex to naïve T-cell

Re-exposure to same haptensresults in activation of hapten-specific T cells in the skin

Inflammation leading to characteristic skin lesions

Pathophysiology contact urticaria syndrome: Type I hypersensitivity

Allergen exposure leads to production of specific IgE

Subsequent exposures result in degranulation of mast cells with release of histamine, cytokines etc. Skin prick tests

Prick prick testsSpecific IgE

High risk occupations for occupational contact dermatitis

Common allergens

Common irritant exposures at work

• Wet work

• Frequent hand washing

• Use of occlusive gloves

• Exposure to soaps/alkalis

• Exposure to acids

• Exposure to solvents

• Mechanical irritation (friction)

Evaluating a patient with possible occupational dermatitis

Step 1: Personal and occupational history

• Pre-existing skin or atopic conditions

• When did symptoms start? How does rash present? Associated Type 1 allergy symptoms?

• Does condition improve with time away from work, and worsen on return to work?

• Other exposures (hobbies, second job, household chores etc)

Occupational history

• Important to obtain detailed description of tasks

• Ascertain presence of chemical hazards, particularly known allergens

• Consider presence of irritants in the workplace:• Wet work• Occlusive gloves• Frequent handwashing• Detergents/soaps/solvents/acids/alkalis• Mechanical irritants (friction)

Step 2: Clinical examination

• Skin examination

• Other systems as necessary

Distinguishing irritant from allergic contact dermatitisChronic irritant contact dermatitis Allergic contact dermatitis

Occurs after prolonged contact with irritants (days to months)

Delayed hypersensitivity reaction – usually appears approximately 24 hours after exposure to allergen

Distribution tends to be limited to site of irritant exposure. May affect web spaces with wet work.

May be in a distribution of direct contact with allergen, but may ‘spill’ beyond. May appear at distant sites

Tends to present more as dry, fissured skin with burning rather than itch

Acute presentation has hallmarks of acute eczema –erythema, vesicles, itch. Chronic includes hyperpigmentation, lichenification

No activated T-cells: Negative patch tests Activated T-cells: Positive patch test to a relevant contact allergen

Step 3: Patch testing for delayed hypersensitivity

• On the back

• Commercial allergens &

work agents

• Contra-indications:• Active dermatitis on back• Immunosuppressive treatment• Recent tan/sunburn• (Pregnancy)• (Breastfeeding)

Patch test reading

• Left in situ 48 hours

• Read at 72 hours

• Relevance of positive reactions

Source: www.smartpractice.com

Step 4: Other special investigations

• Biopsy

• Fungal scraping

• To exclude: • Psoriasis

• Tinea manuum

Hyperkeratotic irritant contact dermatitis Psoriasis

Prick prick testing & specific IgE

• Not for allergic contact dermatitis

• Performed rarely as protein contact dermatitis and contact urticariaare far less common than contact dermatitis

• Suggested by history of immediate reaction• itch, wheal & flare

Step 5: Workplace assessment

• Difficult to do risk assessment for skin exposure

• No methods for measuring skin exposure directly

• Incomplete data about safe exposure levels

• Time consuming to do as wide range of chemicals and tasks, and toxicology may not be obvious

Management of occupational skin disease

Management of the patient

• Avoidance of irritant exposures

• Allergen avoidance

• Topical steroids: Potent (Dovate) weaning to milder (Lenovate/Persivate)

• Emollients: Cetomacrogol/HEB preferable to aqueous cream

Avoiding irritant exposures• Avoid soaps and grit cleansers – rather wash with emollients

• For healthcare workers – alcohol sanitiser only unless hands visibly soiled

• Frequent application emollients • Barrier creams do not prevent absorption of chemicals

• Try to ensure hands are dry in gloves • Wear cotton liners inside occlusive rubber gloves. Replace liners as soon as they

become wet (will need several pairs)

• Wear gloves above the elbow for wet work, not short gloves

• Avoid direct contact with solvents, alkalis, acids

When to refer for specialist assessment?

• Contact dermatitis does not improve with usual treatment and irritant avoidance.

• History and examination suggest exposure to allergens rather than irritants, and this warrants further investigation.

• For compensation purposes or workplace interventions.

Take home messages

• Always consider occupation in hand dermatitis or exposure-pattern dermatitis.

• Start by addressing irritant exposures and appropriate steroid and emollient use

• Refer/investigate further if not responding to appropriate treatment & irritant avoidance in a couple of months; if recurrent episodes; or if concerning history.

• Allergen avoidance and job modifications mainstay of treatment for allergic contact dermatitis.

Referral/advice centres for assistance with occupational diseases• Cape Town

• Groote Schuur Hospital (E16) Occupational Medicine Clinic (specify Dermatology for skin cases), (021) 404 4369

• Tygerberg Hospital, Respiratory Clinic, (021) 938 5524

• Johannesburg• National Institute of Occupational Health, Braamfontein, (011) 712 6400

• Durban• King Edward Hospital, Occupational Medicine Clinic, (031) 360 3512/3 or (031) 260

4507

Useful websites

• www.labour.gov.za

• www.hse.gov.uk

• www.cdc.gov

http://www.labour.gov.za/http://www.hse.gov.uk/http://www.cdc.gov/

References

• Occupational skin diseases and dermal exposure in the European Union (EU-25): policy and practice overview. European Agency for Safety and Health at Work. Belgium, 2008.

• Belsito DV. Occupational contact dermatitis: etiology, prevalence and resultant impairment/disability. J Am Acad Derm 2005; 53: 303-13.

• Personen et al. Patch test results of the European baseline series among patients with occupational contact dermatitis across Europe –analyses of the European Surveillance System on Contact Allergy Network 2002-2010. Contact Dermatitis 2015; 72:154-163